The losses by pilferage from railway freight cars such as box cars and including highway trucks and trailers are a large factor in the cost of shipment of lading. These losses particularly occur when the cars are in the yard or on a siding awaiting transfer to an unloading station or to another destination, even though locks and seals are provided for the doors and the seals are not intentionally broken except when the car is standing along an unloading dock. The locks and seals are readily accessible from the ground both with sliding doors and plug types of doors, both of which doors are in common use at the present day. Even though the locks for these doors are sturdy their accessibility from the ground requires little ingenuity and energy to release the locks with the result that the freight yards must be continuously policed and even then the loss due to pilferage is substantial.